// Numbas version: exam_results_page_options {"name": "Unit circle definition (radians)", "extensions": [], "custom_part_types": [], "resources": [], "navigation": {"allowregen": true, "showfrontpage": false, "preventleave": false, "typeendtoleave": false}, "question_groups": [{"pickingStrategy": "all-ordered", "questions": [{"preamble": {"js": "", "css": ""}, "parts": [{"prompt": "

What are the coordinates of the point $B$?

\n

$B=\\Large($ [[0]], [[1]] $\\Large)$

\n

\n

Note: Suppose you wanted to enter $\\tan(\\theta)$, then you would type tan(theta) including the brackets.

", "variableReplacements": [], "showFeedbackIcon": true, "type": "gapfill", "variableReplacementStrategy": "originalfirst", "gaps": [{"vsetrange": [0, 1], "checkingaccuracy": 0.001, "answer": "cos(theta)", "vsetrangepoints": 5, "marks": 1, "variableReplacementStrategy": "originalfirst", "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": [], "showpreview": true, "scripts": {}, "type": "jme", "variableReplacements": [], "showCorrectAnswer": true, "showFeedbackIcon": true}, {"vsetrange": [0, 1], "checkingaccuracy": 0.001, "answer": "sin(theta)", "vsetrangepoints": 5, "marks": 1, "variableReplacementStrategy": "originalfirst", "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": [], "showpreview": true, "scripts": {}, "type": "jme", "variableReplacements": [], "showCorrectAnswer": true, "showFeedbackIcon": true}], "scripts": {}, "marks": 0, "showCorrectAnswer": true}, {"prompt": "

What is the slope of the line segment $OB$?

\n

$m_{OB}=$ [[0]]

", "variableReplacements": [], "showFeedbackIcon": true, "type": "gapfill", "variableReplacementStrategy": "originalfirst", "gaps": [{"vsetrange": [0, 1], "checkingaccuracy": 0.001, "answer": "tan(theta)", "vsetrangepoints": 5, "marks": 1, "variableReplacementStrategy": "originalfirst", "checkingtype": "absdiff", "checkvariablenames": false, "expectedvariablenames": [], "showpreview": true, "scripts": {}, "type": "jme", "variableReplacements": [], "showCorrectAnswer": true, "showFeedbackIcon": true}], "scripts": {}, "marks": 0, "showCorrectAnswer": true}], "name": "Unit circle definition (radians)", "variables": {}, "variable_groups": [], "tags": [], "metadata": {"description": "

Unit circle definition of sin, cos, tan using degrees

", "licence": "Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International"}, "extensions": [], "rulesets": {}, "statement": "

Let $A$ be the point $(1,0)$, $O$ be the origin $(0,0)$, and $B$ be a point on the unit circle (the circle centred at the origin, $O$, with radius 1). 

\n

Suppose that the line segment $OA$ would have to travel $\\theta$ radians anti-clockwise around the origin to get to the line segment $OB$. Or in other words, $A$ is $\\theta$ radians anti-clockwise from the positive $x$-axis.

", "advice": "

The point on the unit circle, $\\theta$ radians anti-clockwise from the positive $x$-axis, is $(\\cos(\\theta),\\sin(\\theta))$. This is the unit circle definition of sine and cosine. You can think of this as being a generalisation of the right-angled trigonometry that takes place in the first quadrant of the Cartesian plane.

\n

\n

The definition of $\\tan(\\theta)$ can be thought of as $\\dfrac{\\sin(\\theta)}{\\cos(\\theta)}$ but this is just the gradient of the line segment connecting the origin to the point on the unit circle.

\n

The following applet is for you to investigate the relationship between the trigonometric functions and the unit circle by moving the point $B$ around the circle.

\n

\n
", "functions": {}, "ungrouped_variables": [], "variablesTest": {"maxRuns": 100, "condition": ""}, "type": "question", "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}]}], "contributors": [{"name": "Ben Brawn", "profile_url": "https://numbas.mathcentre.ac.uk/accounts/profile/605/"}]}